As shown in FIG. 12 (which is a partial plan view showing a perpendicular magnetic recording head), a recording magnetic head using a perpendicular magnetic recording method that magnetizes a recording medium in a direction perpendicular to a medium surface of the recording medium includes a first magnetic layer (a return-pass layer) 1, a second magnetic layer (a main magnetic pole layer) 2, and coil layers (not shown) for inducing recording magnetic fields on the first magnetic layer 1 and the second magnetic layer 2. The return-pass layer 1 and the main magnetic pole layer 2 face each other with a predetermined space interposed therebetween in the thickness direction. An induction field generated by a flow of an electric current through the coil layers is induced on the return-pass layer 1 and the main magnetic pole layer 2, and a recording magnetic field enters the recording medium in the direction perpendicular to the medium surface of the recording medium from a front end surface 2a that is flush with a facing surface of the main magnetic pole layer 2 facing the recording medium. The recording magnetic field passes through the recording medium and reaches the return-pass layer 1.
As shown in FIG. 12, the return-pass layer 1 has a substantially rectangular plan shape in the related art. If the plan shape of the return-pass layer is formed in a substantially rectangular shape, the recording magnetic field that passes through the recording medium and reaches the return-pass layer 1 may be concentrated on and to return to the ends (corners) 1b of a front end surface 1a of the return-pass layer 1 flush with the facing surface. A lower part in FIG. 12 is a graph showing a relationship between a position along the front end surface 1a of the return-pass layer 1 in the track-width direction and the intensity of the magnetic field generated toward the medium. As shown in the lower part of FIG. 12, since a strong magnetic field is generated from each of the corners 1b of the front end surface 1a of the return-pass layer 1, a phenomenon that erases a signal written on the recording medium may occur at each of the corners 1b. 
There has been an attempt to position the corners shown in FIG. 12 as far away as possible from the facing surface in the height direction in order to suppress the phenomenon of erasing a recorded signal. That is, as shown in FIG. 13, sloping surfaces 1c and 1c may be formed on both sides of the front end surface 1a of the return-pass layer 1 in the track-width direction (X direction) so that a width between the sloping surfaces in the track-width direction (X direction) gradually increases from the facing surface in the height direction (Y direction).
A structure in which the sloping surfaces 1c and 1c are formed on both sides of the front end surface 1a of the return-pass layer 1 is disclosed in each of JP-A Nos. 2004-39148 and 2004-12740 (corresponding to US Publication Nos. 2004004787A1 and 2004151036A1, respectively).
However, even in the case of the structure shown in FIG. 13, corners 1e are formed between the front end surface 1a of the return-pass layer 1 and each of the sloping surfaces 1c, respectively. As a result, since a recording magnetic field may be concentrated on and return to each of the corners 1e, a strong magnetic field may be generated from each of the corners 1e toward the medium. For this reason, it is not possible to appropriately suppress the phenomenon of erasing a recorded signal in the structure shown in FIG. 13.